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Abstract:

In some embodiments, an archery bow comprises a frame supporting a first
limb and a second limb. A first rotatable member is supported by the
first limb and arranged to rotate about a first rotation axis. The first
rotatable member comprises a cam track. A second rotatable member is
supported by the second limb and arranged to rotate about a second
rotation axis. The second rotatable member comprises a synchronizer
track. A bowstring extends between the first rotatable member and the
second rotatable member. A power cable is arranged to be taken up on the
cam track and fed out from the synchronizer track as the bow is drawn.
The synchronizer track is circular and a centerpoint of the synchronizer
is offset from the second rotation axis.

Claims:

1. A rotatable member for use in a compound bow comprising: a body
arranged to rotate about an axis, said rotatable member comprising a
bowstring track, a power cable track and a synchronizer track, said
bowstring track defining a circular arc, said power cable track defining
a circular arc, said synchronizer track defining a circular arc; wherein
each of said bowstring track, said power cable track and said
synchronizer track define a centerpoint that is offset from said axis.

2. The rotatable member of claim 1, wherein each of said centerpoints is
aligned in a plane that includes said axis.

3. The rotatable member of claim 1, wherein said centerpoint of said
bowstring track is offset from said centerpoint of said power cable
track.

4. The rotatable member of claim 1, wherein said centerpoint of said
bowstring track is aligned upon said centerpoint of said power cable
track.

5. The rotatable member of claim 1, wherein a radius of said power cable
track is smaller than a radius of said bowstring track.

6. The rotatable member of claim 1, wherein said bowstring track
comprises a radius that is similar to a radius of said power cable track.

7. The rotatable member of claim 6, wherein said centerpoint of said
bowstring track aligned upon said centerpoint of said power cable track.

8. The rotatable member of claim 7, wherein each of said centerpoints is
aligned in a plane that includes said axis.

9. An archery bow comprising: a frame supporting a first limb and a
second limb; a first rotatable member supported by the first limb and
arranged to rotate about a first rotation axis, the first rotatable
member comprising a cam track; a second rotatable member supported by the
second limb and arranged to rotate about a second rotation axis, the
second rotatable member comprising a synchronizer track; a bowstring
extending between the first rotatable member and the second rotatable
member; a power cable arranged to be taken up on the cam track and fed
out from the synchronizer track as the bow is drawn; wherein the
synchronizer track is circular and a centerpoint of the synchronizer is
offset from the second rotation axis.

10. The archery bow of claim 9, wherein the power cable extends around
the axis of rotation, crosses itself and attaches to the second rotatable
member.

11. The archery bow of claim 10, the synchronizer track oriented in a
plane, the second rotatable member comprising a cable terminal that is
offset from the plane, the power cable attached to the cable terminal.

12. The archery bow of claim 9, wherein the cam track is circular and a
centerpoint of the cam track is offset from the first rotation axis.

13. The archery bow of claim 12, the first rotatable member comprising a
bowstring track, the bowstring track being circular, a centerpoint of the
bowstring track offset from the first rotation axis.

14. The archery bow of claim 13, wherein a radius of the bowstring track
is equal to a radius of the power cable track.

15. The archery bow of claim 9, the power cable applying a force to the
second rotatable member, the force having a moment arm distance, wherein
the moment arm distance is greater in a fully drawn condition than in a
brace condition.

16. The archery bow of claim 15, wherein the moment arm distance reaches
a maximum in the fully drawn condition.

17. The archery bow of claim 9, the first rotatable member comprising a
synchronizer track having a circular shape and a centerpoint offset from
the first rotation axis.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Patent Application No.
62/085,208, filed Nov. 26, 2014, the entire disclosure of which is hereby
incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] This invention relates generally to compound bows and more
specifically to compound bows having a synchronizing feature.

[0003] Compound bows having synchronizing features are known in the art,
for example as disclosed by Ketchum in U.S. Pat. No. 3,990,425, the
entire disclosure of which is hereby incorporated herein by reference.
Since the Ketchum invention, compound bows have continued to advance in
design. A more advanced design can provide better performance, but the
advanced design generally more complicated, and may be more prone to
coming out of adjustment, etc.

[0004] There remains a need for novel bow designs that provide benefits
over previous designs.

[0005] All US patents and applications and all other published documents
mentioned anywhere in this application are incorporated herein by
reference in their entirety.

[0006] Without limiting the scope of the invention a brief summary of some
of the claimed embodiments of the invention is set forth below.
Additional details of the summarized embodiments of the invention and/or
additional embodiments of the invention may be found in the Detailed
Description of the Invention below.

[0007] A brief abstract of the technical disclosure in the specification
is provided as well only for the purposes of complying with 37 C.F.R.
1.72. The abstract is not intended to be used for interpreting the scope
of the claims.

BRIEF SUMMARY OF THE INVENTION

[0008] In some embodiments, an archery bow comprises a frame supporting a
first limb and a second limb. A first rotatable member is supported by
the first limb and arranged to rotate about a first rotation axis. The
first rotatable member comprises a cam track. A second rotatable member
is supported by the second limb and arranged to rotate about a second
rotation axis. The second rotatable member comprises a synchronizer
track. A bowstring extends between the first rotatable member and the
second rotatable member. A power cable is arranged to be taken up on the
cam track and fed out from the synchronizer track as the bow is drawn.
The synchronizer track is circular and a centerpoint of the synchronizer
is offset from the second rotation axis.

[0009] In some embodiments, a rotatable member for use in a compound bow
comprises a body arranged to rotate about an axis comprising a bowstring
track, a power cable track and a synchronizer track. The bowstring track
defines a circular arc, the power cable track defines a circular arc and
the synchronizer track defines a circular arc. Each of the bowstring
track, power cable track and synchronizer track define a centerpoint that
is offset from the rotation axis.

[0010] These and other embodiments which characterize the invention are
pointed out with particularity in the claims annexed hereto and forming a
part hereof However, for a better understanding of the invention, its
advantages and objectives obtained by its use, reference can be made to
the drawings which form a further part hereof and the accompanying
descriptive matter, in which there are illustrated and described various
embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] A detailed description of the invention is hereafter described with
specific reference being made to the drawings.

[0012] FIG. 1 shows an embodiment of a crossbow.

[0013] FIG. 2 shows an embodiment of rotating members.

[0014] FIG. 3 shows an underside view of an embodiment of rotating
members.

[0015] FIG. 4 shows an embodiment of a rotatable member.

[0016] FIG. 5 shows the rotatable member of FIG. 4 from the opposite side.

[0017] FIG. 6 shows an embodiment of a vertical bow.

[0018] FIG. 7 shows an angled view of an embodiment of a rotatable member.

[0019] FIG. 8 shows the rotatable member of FIG. 7 from another angle.

[0020] FIG. 9 shows an angled view of another embodiment of a rotatable
member.

[0021] FIG. 10 shows the rotatable member of FIG. 9 from another angle.

[0022] FIG. 11 shows an angled view of another embodiment of a rotatable
member.

[0023] FIG. 12 shows the rotatable member of FIG. 11 from another angle.

[0024] FIG. 13 shows an embodiment of a compound bow in a brace condition.

[0025] FIG. 14 shows an embodiment of a compound bow in a drawn condition.

[0026] FIG. 15 shows an embodiment of a rotatable member in an embodiment
of a compound bow.

DETAILED DESCRIPTION OF THE INVENTION

[0027] While this invention may be embodied in many different forms, there
are described in detail herein specific embodiments of the invention.
This description is an exemplification of the principles of the invention
and is not intended to limit the invention to the particular embodiments
illustrated.

[0028] For the purposes of this disclosure, like reference numerals in the
figures shall refer to like features unless otherwise indicated.

[0029] The compound bow disclosed herein can be used in any suitable
device, such as crossbows and traditional vertical bows.

[0031] In some embodiments, a crossbow 10 comprises any suitable feature
or combination of features as disclosed in US 2012/0298087, US
2013/0118463, US 2014/0069401, US 2014/0069402, US 2014/0069403, US
2014/0069404 and US 2014/0261357, the entire disclosures of which are
hereby incorporated herein by reference.

[0032] FIG. 2 shows an embodiment of a compound bow 20 portion of a
crossbow 10 in greater detail. Desirably, the compound bow 20 comprises a
frame 22 arranged to support a first limb 24 and a second limb 26. When
the compound bow 20 is used in a crossbow 10, the frame 22 can comprise a
prod 18 that is attached to the stock 12. In some embodiments, each limb
24, 26 is received in a limb cup 28, for example as disclosed in U.S.
Pat. No. 8,453,635. Desirably, the first limb 24 supports a first
rotatable member 30 and the second limb supports a second rotatable
member 32. The first rotatable member 30 is arranged to rotate about a
first axis 31 and the second rotatable member 32 is arranged to rotate
about a second axis 33. In some embodiments, one or more limbs (e.g. 24)
comprise split limb elements 24a, 24b, and the associated rotatable
member (e.g. 30) is oriented between the split limb elements 24a, 24b. In
some embodiments, the shapes of the rotatable members 30, 32 are mirror
images of one another.

[0033] FIG. 3 shows an underside view of an embodiment of a crossbow 10.

[0034] FIG. 4 shows a top view of an embodiment of the first rotatable
member 30, and

[0035] FIG. 5 shows a bottom view.

[0036] With reference to FIGS. 3-5, desirably, the compound bow 20
comprises a bowstring 40 that extends between the first rotatable member
30 and the second rotatable member 32. In some embodiments, a first end
of the bowstring 40 is attached to the first rotatable member 30 and a
second end of the bowstring 40 is attached to the second rotatable member
32.

[0037] In some embodiments, each rotatable member 30, 32 comprises a
bowstring track 42 and a bowstring terminal 44. In a brace condition, a
portion of the bowstring 40 occupies the bowstring track 42 and
terminates on the bowstring terminal 44. As the bowstring 40 is drawn,
the rotatable members 30, 32 rotate and bowstring is fed out from the
bowstring tracks 42.

[0038] In some embodiments, the bowstring track 42 is circular in shape.
For example, a centerpoint 43 (see FIGS. 4&5) can be defined, and a
radius is defined between the centerpoint 43 and the bowstring track 42.
In some embodiments, a central axis of the bowstring track 42 is circular
in shape, extends in a circle or extends along an arc having a constant
radius. In some embodiments, the centerpoint 43 of the bowstring track 42
is offset from the rotatable member axis 31.

[0039] Desirably, the compound bow 20 comprises a first power cable 50
extending between the first and second rotatable members 30, 32.
Desirably, the first power cable 50 is arranged to pull the limbs 24, 26
together as the bow 20 is drawn. In some embodiments, the compound bow 20
comprises a second power cable 60. In some embodiments, the first and
second power cables 50, 60 are mirrored.

[0040] In some embodiments, the one or both rotatable member(s) 30, 32
comprise a power cable track 52 and a synchronizer track 54. In some
embodiments, each power cable 50, 60 comprises a first end arranged to be
taken up by the power cable track 52 of one roatable member (e.g. 30) and
a second end arranged to be fed out from the synchronizer track 54 of the
other rotatable member (e.g. 32) as the bow is drawn.

[0041] In some embodiments, the power cable track 52 defines a circular
shape. For example, a centerpoint 53 (see FIGS. 4&5) can be defined, and
a radius is defined between the centerpoint 53 and the power cable track
52. In some embodiments, a central axis of the power cable track 52
extends along a circular arc, for example having a constant radius. In
some embodiments, the centerpoint 53 is offset from the rotatable member
axis 31.

[0042] In some embodiments, the centerpoint 53 of the power cable track 52
is aligned with the centerpoint 43 of the bowstring track 42. From the
viewing angle of FIG. 4 or 5, the centerpoints 43, 53 are juxtaposed. As
the bowstring track 42 is generally offset from the power cable track 52
(e.g. .vertically offset), in some embodiments, a line extending between
the centerpoints 43, 53 extends parallel to the axis of rotation 31.

[0043] In some embodiments, the bowstring track 42 extends parallel to the
power cable track 52. In some embodiments, a radius distance from the
centerpoint 43 to the bowstring track 42 is the same as a radius distance
from the centerpoint 53 to the power cable track 52.

[0044] In some embodiments, the synchronizer track 54 defines a circular
shape. For example, a centerpoint 55 (see FIGS. 4&5) can be defined, and
a radius is defined between the centerpoint 55 and the synchronizer track
54. In some embodiments, a central axis of the synchronizer track 54
extends along an arc that has a constant radius from the centerpoint 55.

[0045] Desirably, the centerpoint 55 of the synchronizer track 54 is
offset from the rotatable member axis 31.

[0046] In some embodiments, a line/axis 62 extends between the axis of
rotation 31 and the centerpoint 43 of the bowstring track 42, and the
centerpoint 55 of the synchronizer track 54 is oriented on the line/axis
62. In some embodiments, a line/axis 62 extends between the axis of
rotation 31 and the centerpoint 53 of the power cable track 52, and the
centerpoint 55 of the synchronizer track 54 is oriented on the line/axis
62.

[0047] FIG. 6 shown an embodiment of a vertical bow having rotatable
members 30, 32 as described herein. The frame 22 can comprise a riser 19
that supports the limbs 24, 26. The riser 19 can support a cable guard 21
arranged to bias cables in a direction lateral to the shooting axis.

[0048] The bow 20 desirably comprises a bowstring 40 and a power cable 50.
In some embodiments, the bow 20 comprises a second power cable 60. The
features of the rotatable members 30, 32 can be similar to other
rotatable members 30, 32 as described herein, for example comprising a
bowstring track 42, a power cable track 52 and a synchronizer track 54.

[0049] FIG. 7 shows an embodiment of a rotatable member 30 viewed at an
angle. FIG. 8 shows the rotatable member 30 of FIG. 7 as viewed along the
axis of rotation 31.

[0050] In some embodiments, a bowstring track 42 extends around a
perimeter of the rotatable member 30. In some embodiments, the bowstring
track 42 follows a circular arc having a centerpoint 43 that is offset
from the axis of rotation 31.

[0051] In some embodiments, a power cable track 52 extends around a
perimeter of the rotatable member 30. In some embodiments, the power
cable track 52 follows a circular arc having a centerpoint 53 that is
offset from the axis of rotation 31.

[0052] In some embodiments, the centerpoint 43 of the bowstring track 42
is aligned with the centerpoint 53 of the power cable track 52. This is
shown in FIG. 8. In some embodiments, a reference line that extends
through both centerpoints 43, 53 extends parallel to the axis of rotation
31.

[0053] In some embodiments, a radius of the bowstring track 42 is similar
to a radius of the power cable track 52. In some embodiments, the
bowstring track 42 and power cable track 52 extend parallel to one
another, for example being oriented in parallel planes.

[0054] In some embodiments, the rotatable member 30 comprises a
synchronizer track 54. In some embodiments, the synchronizer track 54
follows a circular arc having a centerpoint 55 that is offset from the
axis of rotation 31.

[0055] In some embodiments, a line/axis 62 extends between the axis of
rotation 31 and the centerpoint 43 of the bowstring track 42, and the
centerpoint 55 of the synchronizer track 54 is oriented on the line/axis
62. In some embodiments, a line/axis 62 extends between the axis of
rotation 31 and the centerpoint 53 of the power cable track 52, and the
centerpoint 55 of the synchronizer track 54 is oriented on the line/axis
62. Due to the offset locations of the centerpoints 43, 53, 55, the
line/axis 62 as viewed in FIG. 8 represents a plane, wherein the axis of
rotation 31 extends in the plane and the centerpoints 43, 53, 55 are
oriented in the plane.

[0056] In some embodiments, a rotatable member 30 includes a first
terminal post 66 and a second terminal post 68, which are both oriented
in a common plane. In some embodiments, the terminal posts 66, 68 are
oriented in a plane that includes the power cable track 52.

[0057] FIG. 9 shows an embodiment of a rotatable member 30 viewed at an
angle. FIG. 10 shows the rotatable member 30 of FIG. 9 as viewed along
the axis of rotation 31.

[0058] In some embodiments, a bowstring track 42 extends around a
perimeter of the rotatable member 30. In some embodiments, the bowstring
track 42 follows a circular arc having a centerpoint 43 that is offset
from the axis of rotation 31.

[0059] In some embodiments, the power cable track 52 follows a circular
arc having a centerpoint 53 that is offset from the axis of rotation 31.

[0060] In some embodiments, the centerpoint 43 of the bowstring track 42
is aligned with the centerpoint 53 of the power cable track 52. This is
shown in FIG. 10. In some embodiments, a reference line that extends
through both centerpoints 43, 53 extends parallel to the axis of rotation
31.

[0061] In some embodiments, a radius of the bowstring track 42 is
different from a radius of the power cable track 52. In some embodiments,
a radius of the power cable track 52 is smaller than a radius of the
bowstring track 42. In some embodiments, the bowstring track 42 and power
cable track 52 comprise offset curves.

[0062] In some embodiments, the rotatable member 30 comprises a
synchronizer track 54. In some embodiments, the synchronizer track 54
follows a circular arc having a centerpoint 55 that is offset from the
axis of rotation 31.

[0063] In some embodiments, a line/axis 62 extends between the axis of
rotation 31 and the centerpoint 43 of the bowstring track 42, and the
centerpoint 55 of the synchronizer track 54 is oriented on the line/axis
62. In some embodiments, a line/axis 62 extends between the axis of
rotation 31 and the centerpoint 53 of the power cable track 52, and the
centerpoint 55 of the synchronizer track 54 is oriented on the line/axis
62. Due to the offset locations of the centerpoints 43, 53, 55, the
line/axis 62 as viewed in FIG. 10 represents a plane, wherein the axis of
rotation 31 extends in the plane and the centerpoints 43, 53, 55 are
oriented in the plane.

[0064] FIG. 11 shows an embodiment of a rotatable member 30 viewed at an
angle. FIG. 12 shows the rotatable member 30 of FIG. 11 as viewed along
the axis of rotation 31.

[0065] In some embodiments, a bowstring track 42 extends around a
perimeter of the rotatable member 30. In some embodiments, the bowstring
track 42 follows a circular arc having a centerpoint 43 that is offset
from the axis of rotation 31.

[0066] In some embodiments, the power cable track 52 follows a circular
arc having a centerpoint 53 that is offset from the axis of rotation 31.

[0067] In some embodiments, the centerpoint 43 of the bowstring track 42
is offset from the centerpoint 53 of the power cable track 52.

[0068] In some embodiments, a radius of the bowstring track 42 is
different from a radius of the power cable track 52. In some embodiments,
a radius of the power cable track 52 is smaller than a radius of the
bowstring track 42. In some embodiments, the bowstring track 42 and power
cable track 52 are non-concentric.

[0069] In some embodiments, the rotatable member 30 comprises a
synchronizer track 54. In some embodiments, the synchronizer track 54
follows a circular arc having a centerpoint 55 that is offset from the
axis of rotation 31.

[0070] In some embodiments, a line/axis 62 extends between the axis of
rotation 31 and the centerpoint 43 of the bowstring track 42, and the
centerpoint 55 of the synchronizer track 54 is oriented on the line/axis
62. In some embodiments, a line/axis 62 extends between the axis of
rotation 31 and the centerpoint 53 of the power cable track 52, and the
centerpoint 55 of the synchronizer track 54 is oriented on the line/axis
62. Due to the offset locations of the centerpoints 43, 53, 55, the
line/axis 62 as viewed in FIG. 10 represents a plane, wherein the axis of
rotation 31 extends in the plane and the centerpoints 43, 53, 55 are
oriented in the plane.

[0071] FIG. 13 shows an embodiment of a compound bow 20 in an undrawn or
brace condition. FIG. 14 shows the crossbow of FIG. 13 in a fully drawn
condition.

[0072] In some embodiments, each of the cables 50, 60 applies a force to
each rotatable member 30, 32. The force from each cable 50, 60 places a
torque on a rotatable member 30, 32 about its respective rotation axis
31, 33. The magnitude of the torque applied by a given cable (e.g. 50) is
equal to the tension force in the cable multiplied by the moment arm
distance (e.g. 70). The moment arm distance 70 is perpendicular to a
vector 72 of the tensile force in the cable 50 and measured between the
rotation axis 31 and the vector 72.

[0073] In some embodiments, the moment arm of the synchronizing end of
each power cable 50, 60 increases as the bow is drawn. FIG. 13 shows the
moment arm of the synchronizing end of each power cable 50, 60 being s
relatively short distance. FIG. 14 shows the bow at full draw, and the
moment arm of the synchronizing ends of the cables 50, 60 is greater than
in FIG. 13. For example, a moment arm 76 of the synchronizing end of the
second power cable 60 at the first rotatable member 30 is greater in the
drawn condition than in the brace condition. In some embodiments, the
moment arm 76 of the synchronizing end of a power cable 60 reaches a
maximum value when the bow is at full draw. In some embodiments, the
moment arm 70 of the cam end of a power cable 50 reaches a minimum value
at full draw.

[0074] FIG. 15 shows an embodiment of a rotatable member 20 on a compound
bow 20. In some embodiments, the synchronizing end of a power cable (e.g.
60) wraps around a synchronizer track 54 and terminates on a terminal
post 66. In some embodiments, the power cable 60 crosses itself,
effectively forming a loop that extends around the rotation axis 31 and
synchronizer track 54. In some embodiments, the power cable 60 also
comprises a terminal loop 67 for attachment to the terminal post 66.

[0075] In some embodiments, the terminal post 66 is located outside of a
plane defined by the synchronizer track 54. As shown in FIG. 15, the
synchronizer track defines a plane oriented orthogonal to the rotation
axis 31. The power cable 60 includes a portion oriented in the plane as
the cable 60 extends around the synchronizer track 54. The power cable 60
further includes a terminal portion that is located outside of the plane,
for example being offset in a direction lateral to the plane. Offsetting
the location of the terminal post 66 allows the cable 60 to cross itself
and terminate in a location that would not be available if the terminal
post 66 was located in the plane of the synchronizer track 54.

[0076] The above disclosure is intended to be illustrative and not
exhaustive. This description will suggest many variations and
alternatives to one of ordinary skill in this field of art. All these
alternatives and variations are intended to be included within the scope
of the claims where the term "comprising" means "including, but not
limited to." Those familiar with the art may recognize other equivalents
to the specific embodiments described herein which equivalents are also
intended to be encompassed by the claims.

[0077] Further, the particular features presented in the dependent claims
can be combined with each other in other manners within the scope of the
invention such that the invention should be recognized as also
specifically directed to other embodiments having any other possible
combination of the features of the dependent claims. For instance, for
purposes of claim publication, any dependent claim which follows should
be taken as alternatively written in a multiple dependent form from all
prior claims which possess all antecedents referenced in such dependent
claim if such multiple dependent format is an accepted format within the
jurisdiction (e.g. each claim depending directly from claim 1 should be
alternatively taken as depending from all previous claims). In
jurisdictions where multiple dependent claim formats are restricted, the
following dependent claims should each be also taken as alternatively
written in each singly dependent claim format which creates a dependency
from a prior antecedent-possessing claim other than the specific claim
listed in such dependent claim below.

[0078] This completes the description of the preferred and alternate
embodiments of the invention. Those skilled in the art may recognize
other equivalents to the specific embodiment described herein which
equivalents are intended to be encompassed by the claims attached hereto.